1 files changed, 73 insertions, 0 deletions
diff --git a/testing/web-platform/tests/selection/onselectionchange-on-document.html b/testing/web-platform/tests/selection/onselectionchange-on-document.html
new file mode 100644
index 0000000000..4e06165377
--- /dev/null
+++ b/testing/web-platform/tests/selection/onselectionchange-on-document.html
@@ -0,0 +1,73 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<link rel="help" href="https://w3c.github.io/selection-api/#selectionchange-event">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<body>
+<div id="container"><br><br></div>
+<script>
+
+promise_test(() => {
+  return new Promise(resolve => {
+    let didFireSelectionChangeEvent = false;
+    document.addEventListener("selectionchange", () => { didFireSelectionChangeEvent = true; resolve(); }, {once: true});
+    getSelection().setPosition(container, 0);
+    assert_false(didFireSelectionChangeEvent);
+  });
+}, "selectionchange event on document fires");
+
+promise_test(() => {
+  return (async function() {
+    let selectionChangeCount = 0;
+    document.addEventListener("selectionchange", () => ++selectionChangeCount);
+    container.innerHTML = '<span><br></span><span><br></span>';
+    getSelection().setPosition(container, 0);
+    assert_equals(selectionChangeCount, 0);
+    getSelection().setPosition(container, 2);
+    assert_equals(selectionChangeCount, 0);
+    await new Promise(setTimeout);
+    assert_equals(selectionChangeCount, 1);
+  })();
+}, "selectionchange event on document fires once");
+
+promise_test(() => {
+  return (async function() {
+    let selectionChangeCount = 0;
+    document.addEventListener("selectionchange", () => ++selectionChangeCount);
+    container.innerHTML = '<span><br></span><span><br></span>';
+    getSelection().setPosition(container, 0);
+    assert_equals(selectionChangeCount, 0);
+    getSelection().setPosition(container, 2);
+    assert_equals(selectionChangeCount, 0);
+    await new Promise(setTimeout);
+    assert_equals(selectionChangeCount, 1);
+    getSelection().setPosition(container, 0);
+    assert_equals(selectionChangeCount, 1);
+    getSelection().setPosition(container, 2);
+    assert_equals(selectionChangeCount, 1);
+    await new Promise(setTimeout);
+    assert_equals(selectionChangeCount, 2);
+  })();
+}, "task to fire selectionchange event gets queued each time selection is mutated");
+
+promise_test(() => {
+  return (async function() {
+    let selectionChangeCount = 0;
+    document.addEventListener("selectionchange", () => {
+      if (!selectionChangeCount) {
+        getSelection().setPosition(container, 2);
+        getSelection().setPosition(container, 0);
+      }
+      ++selectionChangeCount;
+    });
+    container.innerHTML = '<b><br></b><b><br></b>';
+    getSelection().setPosition(container, 0);
+    assert_equals(selectionChangeCount, 0);
+    await new Promise(setTimeout);
+    assert_equals(selectionChangeCount, 1);
+    await new Promise(setTimeout);
+    assert_equals(selectionChangeCount, 2);
+  })();
+}, "has scheduled selectionchange event is set to false at the beginning of a task to fire selectionchange event");
+
+</script>